well i took on the project of changing my rear end fluid and ever scince its had a steady leak. nothing major but its not right. so what is the best goo to seal the hogs head cover with? anyone know.

p.s i did clear off all the old silicone off the housing and the cover. but to no avail i still have a small leak

 

Well make sure to get everything clean, use 100% silicon, let it skin then install. Another thing to check is your vent tube, any pressure will push out your seal on the axle tube or cover.

 

i might need to check my vent tube. and i dont think i let it skin over either. i just put it on the cover and put it on.

 

Clean the surfaces well with disk brake cleaner.

Use a Permatex form a gasket type silicone.
I applied the silicone around the diameter of the differential, around the inside of the bolt holes.
I installed the cover and let cure overnight before filling with 75/140.
No leaks for over a year.

 

What Heatstroked said except I only waited 5 minutes before adding the ERL! That Permatex stuff is Dynomite - not cheap tho.

 

I did the same thing and no leaks for about 7 months now.

 

The grey stuff that Ford sells is supposed to be the best there is, but I think plain old Permatex blue form-a-gasket works as well as anything. The trick is to either let the bead of sealant skin for 20 minutes or so before you install the cover, which always works for me, or to let it cure before you put fluid to it...like Heat and JD have had success with.

Another option would be to go down to the parts store and get a paper gasket for it.

 

Don't know what all the fuss is about. Clean the cover and the pig with solvent. Apply thin coat of Permatex blue to both cover and pig. I don't wait for them to skin. Bolt cover on. Let set up for about 1/2 hour and fill with lube. Used this process for many years on the Ford, Chevy and the Dodge and have never had an axle cover leak. Now that I've said that gona knock on some wood.

Randy

 

Out of curiosity, what is the benefit of changing the diff oil? According to the manual you should never have to change it.

 

The owner's manual says to change it every 100K miles or if the axle has been submerged in water. I changed mine for a second time at about 165K because I had to change my rear bearings.

 

Don't believe a word of that! Out of the 5 trucks that I have owned in my life three of them had the oil come out completly broken down with less than 50k on them. Made me rethink the oil change schedules for everything else on the truck. You know, transmission, engine. If the rear axle gets so foamy and thin in less than 50k, then what's going on inside the transmission, transfer case, engine??? It made me a big fan of regular and frequent fluid changes everywhere.

 

Yea I gotta go with Kwik on this one - that's a LOT of miles on that relatively little bit of oil in there. Unless I have a problem first - I was figuring on changing mine every 50K or so. I changed the rear oil in my old truck - slapped the cover on, waited a 1/2 hour and filled it with oil. The next morning - all (looked like it anyway) the oil was on the drive instead of in the diff. The next time I waited 24 hours and it held fine - so I wouldn't rush it.

 

well i waited overnight to fill it so i dont know what has been going on. probally just my luck but i am sure if i were to do it again i wouldnt have any problems

 

The trick to get the silicone to seal is to completly degrease the contact surfaces. After you get the cover off and clean out the yucky oil and are ready to put the cover back on, get a can of brake cleaner spray and a bunch of rags. Thoroughly and I mean THOROUGHLY, and aggressively remove any oil from the sealing surfaces on both the pumpkin and the cover. Make sure that there is no oil going to run out of the housing and over the sealing surface. Only then is it ready to have the silicone applied. Then it will not leak.
Now while the cover is off, why not drill a small hole in the bottom of the cover and weld a nut on the inside, run a short bolt with a sealing washer through and you now have a handy drain plug for a much easier rear axle servicing.